This invention relates to occupant restraint cushions and, more particularly, to an inflatable occupant restraint cushion having multiple compartments, each compartment having a preset shape and mode of operation suited to the part of the vehicle occupant's body intended to engage or impact such compartment.
It is known to provide occupant restraint cushions which are internally divided into compartments by internal walls. This is done for various reasons, such as: controlling the pressure differential between one compartment and another compartment during inflation of the cushion or during occupant engagement with the cushion; controlling the shape of the cushion; providing for the aspiration of ambient atmosphere into the cushion as it is inflated; and controlling deflation of the cushion.
The occupant restraint cushion of this invention has upper and lower compartments, each of which has a preset shape suited for respective engagement by the head and torso of a vehicle occupant. The upper compartment is subdivided into subcompartments which are operative independently of each other to control movement of the head of the occupant relative thereto. The compartments and subcompartments are in fluid communication with each other and all are at the same pressure when the cushion is inflated. The head engageable front walls of the subcompartments of the upper compartment of the cushion are shaped to control the membrane forces applied by such walls to the head of the occupant when engaged therewith.
In the preferred embodiment of the invention, the occupant restraint cushion is subdivided into the upper and lower compartments by a generally horizontal internal tether or wall having its front and rear edges sewn or secured to corresponding front and rear walls of the cushion, with the front and rear walls of the cushion being designated as such with respect to the occupant. The general horizontal subdividing wall and one or more additional generally horizontal walls angularly divergent thereto control the shape or curvature of the head engageable front wall of the upper compartment of the cushion to limit the membrane forces applied by such wall to the head of the occupant when engaged therewith. The generally horizontal walls taper between their front and rear secured edges to space their side edges from the side walls of the cushion and permit pressure fluid to freely circulate between the upper and lower compartments of the cushion.
One or more vertical subdividers or pairs of slightly spaced external vertical walls subdivide the front section of the upper compartment into individually operative subcompartments, the front walls of which are provided by the front wall of the upper compartment. The vertical walls of each pair have their lower edges sewn or secured to the subdividing generally horizontal wall and extend freely upwardly through respective slots or openings in the one or more additional angularly divergent generally horizontal walls. The rear edges of the walls of each pair are sewn or secured to each other and the forward edges of such walls are each secured to the front wall of the upper compartment adjacent one side of a slot or opening therein. The head of the occupant may engage the front wall of one or more subcompartments. By providing independently operative subcompartments, movement of the head of the occupant relative to the upper compartment is controlled.
The number of vertical subdividers determines the number of individually operative subcompartments in the front section of the upper compartment. If one such subdivider is provided, two individually operative subcompartments will result. Each will include an outer side wall provided by the outer side wall of the upper compartment, an inner side wall provided by one of the walls of the subdivider, a front wall provided by the front wall of the upper compartment, and a lower wall provided by the subdividing generally horizontal wall. The individually operative subcompartments all open to the rear section of the upper compartment and can be of the same or different size. If more than one vertical subdivider is provided, the number of resulting individually operative subcompartments will be equal to the number of such subdividers plus one.
The primary feature of this invention is that it provides an inflatable occupant restraint cushion having multiple compartments, each having a preset shape and mode of operation suited to the part of the occupant's body intended to engage such compartment. Another feature is that the cushion has upper and lower compartments intended for respective engagement by the head and torso of the occupant. A further feature is that the front or head engageable wall of the upper compartment is shaped to control the membrane forces applied to the head of the occupant impacting such wall. Yet another feature is that the compartments are at the same pressure when the cushion is inflated. Yet a further feature is that the upper compartment is subdivided into subcompartments, each of which is independently operative when engaged by the head of the occupant. Still another feature is that the upper compartment is separated from the lower compartment by a generally horizontal subdividing wall which permits pressure fluid to circulate between the upper and lower compartments. Still a further feature is that the subcompartments of the upper compartment are provided by one or more pairs of external vertical walls or subdividers extending between one of the generally horizontal subdividing wall and the front or head engageable wall of the upper compartment. Yet an additional feature is that the front or head engageable wall of the upper compartment is preshaped by the horizontal subdividing wall and additional horizontal walls angularly divergent thereto.